Re: [Xen-devel] [PATCH: Lazy Restore] xl restore: Add a new "-l" lazy switch.

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

On Thu, May 29, 2014 at 12:34:47AM +0530, Dushyant Behl wrote:
> Add a new "-l" option to xl restore which implies use of lazy restore.
> Plumb the lazy argument from libxl to libxc. Currently libxc just prints
> a debug message and continue with the conventional process.
> 
> Please note that the lazy restore is to be enabled only for HVM guests.
> If "-l" is passed as an argument to non HVM guest then the process will
> exit with error.

You probably need a documentation entry in the docs directory.
Perhaps also explain what 'lazy' restore is versus the normal
restore path.

Thanks!
> 
> Signed-off-by: Dushyant Behl <myselfdushyantbehl@xxxxxxxxx>
> ---
>  tools/libxc/xc_domain_restore.c  | 11 ++++++++++-
>  tools/libxc/xenguest.h           |  2 +-
>  tools/libxl/libxl_create.c       | 14 +++++++++-----
>  tools/libxl/libxl_internal.h     |  1 +
>  tools/libxl/libxl_save_callout.c |  2 +-
>  tools/libxl/libxl_save_helper.c  |  3 ++-
>  tools/libxl/libxl_types.idl      |  1 +
>  tools/libxl/xl_cmdimpl.c         | 16 ++++++++++++++--
>  tools/libxl/xl_cmdtable.c        |  1 +
>  9 files changed, 40 insertions(+), 11 deletions(-)
> 
> diff --git a/tools/libxc/xc_domain_restore.c b/tools/libxc/xc_domain_restore.c
> index bcb0ae0..f9c506c 100644
> --- a/tools/libxc/xc_domain_restore.c
> +++ b/tools/libxc/xc_domain_restore.c
> @@ -1409,7 +1409,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, 
> uint32_t dom,
>                        unsigned long *console_mfn, domid_t console_domid,
>                        unsigned int hvm, unsigned int pae, int superpages,
>                        int no_incr_generationid, int checkpointed_stream,
> -                      unsigned long *vm_generationid_addr,
> +                      int lazy, unsigned long *vm_generationid_addr,
>                        struct restore_callbacks *callbacks)
>  {
>      DECLARE_DOMCTL;
> @@ -1470,6 +1470,15 @@ int xc_domain_restore(xc_interface *xch, int io_fd, 
> uint32_t dom,
>  
>      DPRINTF("%s: starting restore of new domid %u", __func__, dom);
>  
> +    if ( lazy ) {
> +        DPRINTF("xc: lazy switch enabled for restore\n");
> +
> +        if ( !hvm ) {
> +            PERROR("xc: lazy restore called for non HVM guest");
> +            return 1;
> +        }
> +    }
> +
>      pagebuf_init(&pagebuf);
>      memset(&tailbuf, 0, sizeof(tailbuf));
>      tailbuf.ishvm = hvm;
> diff --git a/tools/libxc/xenguest.h b/tools/libxc/xenguest.h
> index 1f216cd..269275a 100644
> --- a/tools/libxc/xenguest.h
> +++ b/tools/libxc/xenguest.h
> @@ -126,7 +126,7 @@ int xc_domain_restore(xc_interface *xch, int io_fd, 
> uint32_t dom,
>                        unsigned long *console_mfn, domid_t console_domid,
>                        unsigned int hvm, unsigned int pae, int superpages,
>                        int no_incr_generationid, int checkpointed_stream,
> -                      unsigned long *vm_generationid_addr,
> +                      int lazy, unsigned long *vm_generationid_addr,
>                        struct restore_callbacks *callbacks);
>  /**
>   * xc_domain_restore writes a file to disk that contains the device
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index d015cf4..f599280 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -1348,8 +1348,8 @@ static void domain_create_cb(libxl__egc *egc,
>                               int rc, uint32_t domid);
>  
>  static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
> -                            uint32_t *domid,
> -                            int restore_fd, int checkpointed_stream,
> +                            uint32_t *domid, int restore_fd,
> +                            const libxl_domain_restore_params 
> *restore_params,
>                              const libxl_asyncop_how *ao_how,
>                              const libxl_asyncprogress_how *aop_console_how)
>  {
> @@ -1361,10 +1361,14 @@ static int do_domain_create(libxl_ctx *ctx, 
> libxl_domain_config *d_config,
>      cdcs->dcs.guest_config = d_config;
>      cdcs->dcs.restore_fd = restore_fd;
>      cdcs->dcs.callback = domain_create_cb;
> -    cdcs->dcs.checkpointed_stream = checkpointed_stream;
>      libxl__ao_progress_gethow(&cdcs->dcs.aop_console_how, aop_console_how);
>      cdcs->domid_out = domid;
>  
> +    if (restore_params) {
> +        cdcs->dcs.checkpointed_stream = restore_params->checkpointed_stream;
> +        cdcs->dcs.lazy = restore_params->lazy;
> +    }
> +    
>      initiate_domain_create(egc, &cdcs->dcs);
>  
>      return AO_INPROGRESS;
> @@ -1388,7 +1392,7 @@ int libxl_domain_create_new(libxl_ctx *ctx, 
> libxl_domain_config *d_config,
>                              const libxl_asyncop_how *ao_how,
>                              const libxl_asyncprogress_how *aop_console_how)
>  {
> -    return do_domain_create(ctx, d_config, domid, -1, 0,
> +    return do_domain_create(ctx, d_config, domid, -1, NULL,
>                              ao_how, aop_console_how);
>  }
>  
> @@ -1399,7 +1403,7 @@ int libxl_domain_create_restore(libxl_ctx *ctx, 
> libxl_domain_config *d_config,
>                                  const libxl_asyncprogress_how 
> *aop_console_how)
>  {
>      return do_domain_create(ctx, d_config, domid, restore_fd,
> -                            params->checkpointed_stream, ao_how, 
> aop_console_how);
> +                            params, ao_how, aop_console_how);
>  }
>  
>  /*
> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> index c2b73c4..de8fae6 100644
> --- a/tools/libxl/libxl_internal.h
> +++ b/tools/libxl/libxl_internal.h
> @@ -2718,6 +2718,7 @@ struct libxl__domain_create_state {
>      /* private to domain_create */
>      int guest_domid;
>      int checkpointed_stream;
> +    int lazy;
>      libxl__domain_build_state build_state;
>      libxl__bootloader_state bl;
>      libxl__stub_dm_spawn_state dmss;
> diff --git a/tools/libxl/libxl_save_callout.c 
> b/tools/libxl/libxl_save_callout.c
> index e3bda8f..aa8c586 100644
> --- a/tools/libxl/libxl_save_callout.c
> +++ b/tools/libxl/libxl_save_callout.c
> @@ -60,7 +60,7 @@ void libxl__xc_domain_restore(libxl__egc *egc, 
> libxl__domain_create_state *dcs,
>          state->store_domid, state->console_port,
>          state->console_domid,
>          hvm, pae, superpages, no_incr_generationid,
> -        cbflags, dcs->checkpointed_stream,
> +        cbflags, dcs->checkpointed_stream, dcs->lazy,
>      };
>  
>      dcs->shs.ao = ao;
> diff --git a/tools/libxl/libxl_save_helper.c b/tools/libxl/libxl_save_helper.c
> index c36314c..bd0b04a 100644
> --- a/tools/libxl/libxl_save_helper.c
> +++ b/tools/libxl/libxl_save_helper.c
> @@ -242,6 +242,7 @@ int main(int argc, char **argv)
>          int no_incr_genidad =      strtoul(NEXTARG,0,10);
>          unsigned cbflags =         strtoul(NEXTARG,0,10);
>          int checkpointed =         strtoul(NEXTARG,0,10);
> +        int lazy =                 strtoul(NEXTARG,0,10);
>          assert(!*++argv);
>  
>          helper_setcallbacks_restore(&helper_restore_callbacks, cbflags);
> @@ -254,7 +255,7 @@ int main(int argc, char **argv)
>          r = xc_domain_restore(xch, io_fd, dom, store_evtchn, &store_mfn,
>                                store_domid, console_evtchn, &console_mfn,
>                                console_domid, hvm, pae, superpages,
> -                              no_incr_genidad, checkpointed, &genidad,
> +                              no_incr_genidad, checkpointed, lazy, &genidad,
>                                &helper_restore_callbacks);
>          helper_stub_restore_results(store_mfn,console_mfn,genidad,0);
>          complete(r);
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index 52f1aa9..6c8355c 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -282,6 +282,7 @@ libxl_domain_create_info = Struct("domain_create_info",[
>  
>  libxl_domain_restore_params = Struct("domain_restore_params", [
>      ("checkpointed_stream", integer),
> +    ("lazy", integer),
>      ])
>  
>  MemKB = UInt(64, init_val = "LIBXL_MEMKB_DEFAULT")
> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index 5195914..2a10193 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -146,6 +146,7 @@ struct domain_create {
>      int paused;
>      int dryrun;
>      int quiet;
> +    int lazy;
>      int vnc;
>      int vncautopass;
>      int console_autoconnect;
> @@ -2045,6 +2046,7 @@ static uint32_t create_domain(struct domain_create 
> *dom_info)
>      int daemonize = dom_info->daemonize;
>      int monitor = dom_info->monitor;
>      int paused = dom_info->paused;
> +    int lazy = dom_info->lazy;
>      int vncautopass = dom_info->vncautopass;
>      const char *config_file = dom_info->config_file;
>      const char *extra_config = dom_info->extra_config;
> @@ -2237,7 +2239,14 @@ start:
>  
>      if ( restoring ) {
>          libxl_domain_restore_params params;
> +        libxl_domain_create_info *c_info = &d_config.c_info;
> +        if ( lazy && (c_info->type != LIBXL_DOMAIN_TYPE_HVM) ) {
> +            fprintf(stderr, "lazy restore should be called for HVM guest 
> only");
> +            ret = ERROR_INVAL;
> +            goto error_out;
> +        }
>          params.checkpointed_stream = dom_info->checkpointed_stream;
> +        params.lazy = lazy;        
>          ret = libxl_domain_create_restore(ctx, &d_config,
>                                            &domid, restore_fd,
>                                            &params,
> @@ -3925,7 +3934,7 @@ int main_restore(int argc, char **argv)
>      const char *config_file = NULL;
>      struct domain_create dom_info;
>      int paused = 0, debug = 0, daemonize = 1, monitor = 1,
> -        console_autoconnect = 0, vnc = 0, vncautopass = 0;
> +        console_autoconnect = 0, vnc = 0, vncautopass = 0, lazy = 0;
>      int opt, rc;
>      static struct option opts[] = {
>          {"vncviewer", 0, 0, 'V'},
> @@ -3934,7 +3943,7 @@ int main_restore(int argc, char **argv)
>          {0, 0, 0, 0}
>      };
>  
> -    SWITCH_FOREACH_OPT(opt, "FhcpdeVA", opts, "restore", 1) {
> +    SWITCH_FOREACH_OPT(opt, "FhcpdleVA", opts, "restore", 1) {
>      case 'c':
>          console_autoconnect = 1;
>          break;
> @@ -3957,6 +3966,8 @@ int main_restore(int argc, char **argv)
>      case 'A':
>          vnc = vncautopass = 1;
>          break;
> +    case 'l':
> +        lazy = 1;
>      }
>  
>      if (argc-optind == 1) {
> @@ -3977,6 +3988,7 @@ int main_restore(int argc, char **argv)
>      dom_info.config_file = config_file;
>      dom_info.restore_file = checkpoint_file;
>      dom_info.migrate_fd = -1;
> +    dom_info.lazy = lazy;
>      dom_info.vnc = vnc;
>      dom_info.vncautopass = vncautopass;
>      dom_info.console_autoconnect = console_autoconnect;
> diff --git a/tools/libxl/xl_cmdtable.c b/tools/libxl/xl_cmdtable.c
> index 4279b9f..0405c6e 100644
> --- a/tools/libxl/xl_cmdtable.c
> +++ b/tools/libxl/xl_cmdtable.c
> @@ -167,6 +167,7 @@ struct cmd_spec cmd_table[] = {
>        "Restore a domain from a saved state",
>        "[options] [<ConfigFile>] <CheckpointFile>",
>        "-h                       Print this help.\n"
> +      "-l                       Enable lazy restore.\n"
>        "-p                       Do not unpause domain after restoring it.\n"
>        "-e                       Do not wait in the background for the death 
> of the domain.\n"
>        "-d                       Enable debug messages.\n"
> -- 
> 1.9.1
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel